Morpholine has been selected as the first chemical for evaluation. Morpholine is a cheap and widely used solvent. It is a heterocyclic secondary amine that would be expected to be excreted in the urine by way of the tubular organic base excretory mechanism. One of the apparent reasons why this compound has not been studied in the past is the difficulty of the analysis in biological fluids. A considerable amount of time has been devoted to establishing this methodology and we now have a reliable gas chromatographic method for its determination in blood and urine. A rabbit nose exposure unit has been assembled to include automatic GC monitoring. The pharmacokinetics and renal handling of morpholine are being studied.